of great or far-reaching importance or consequence: a momentous day.

Origin of momentous

First recorded in 1645–55; moment + -ous
Related formsmo·men·tous·ly, adverbmo·men·tous·ness, nounun·mo·men·tous, adjectiveun·mo·men·tous·ly, adverbun·mo·men·tous·ness, noun

Synonyms for momentous

Antonyms for momentous Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for momentousness

Historical Examples of momentousness

  • He seemed overwhelmed at the momentousness of the act which he was about to perform.

  • Apart from the splendour of her social position and the momentousness of her political one, she was a person of great wealth.

    Queen Victoria

    Lytton Strachey

  • As I waited the coming of my most powerful customer, I could not keep my mind off the momentousness of the interview before me.

    Frenzied Finance

    Thomas W. Lawson

  • Yes, she had been blindly selfish, and had failed to realize the momentousness of the great questions of the day.

    The Liberty Girl

    Rena I. Halsey

  • Only the irrepressible Tubby was not duly impressed with the momentousness of the occasion.

British Dictionary definitions for momentousness



of great significance
Derived Formsmomentously, adverbmomentousness, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for momentousness



1650s, from moment + -ous to carry the sense of "important" while momentary kept the meaning "of an instant of time." Related: Momentously; momentousness.

Online Etymology Dictionary, © 2010 Douglas Harper